Here is the full list of all 46 Silence achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Find all possible Spot interactions
Finish the game without using the snoopkey
Skip every puzzle
Balance without falling down
Let Sadwick die every time it's possible
Don't prime the bomb
Kick everything possible
Completed the prayer mill story with the dream wheel
Trigger the same game over sequence twice in a row
Find all bugs
Shoot the gate
Fall in all balance checks or fall in the same check 3 times
Finish the game without skipping a text
Go through the mirror
Finish the game without dying
Stay in Silence
You finished chapter three
Dive through the clouds
Send Spot to Kyra
Use the magic boxes to change into all available Spot forms
Grab 10 gold from the well
Discover every possible Spot form
Listen to Kyra
Place candles everywhere possible
Completed the prayer mill story with the life wheel
Spot licked everything
Let spot fly
Get to the gate in 8 steps
Sneeze over the candle
You finished chapter two
Completed the prayer mill story with the death wheel
Let Renie and Noah both pop the bubble
Hit Kyra
Look into the abyss
Spot plunges everywhere
Let the fish get the berries 3 times
Play with the shadows
Let the mushroom fart ten times
Fix the bomb without letting go
Burn the swamp
Taste the everything in the swamp
Lick the mushrooms until you pass out
You finished chapter one
Pull the world worm's tooth
Drop the Noiseball
Prime the bomb